1. It has been 10 years since I last went to Ho Chi Minh City.

(The last time+ S+ last+ Ved/ V2+ was+ khoảng thời gian+ ago

= It has been+ khoảng thời gian+ since+ S+ last+ V2/ Ved)

2. I haven't read a more interesting novel than this one before.

(Đây là cuốn tiểu thuyết thú vị nhất tôi từng đọc.-> Tôi chưa từng đọc một cuốn tiểu thuyết thú vị hơn quyển này trước đó)

3. I haven't been to Bangkok before.

(This is the first time + S+ has/ have+ (ever)+ PII= S+ has/ have+ not/ never+ PII+ before)

4. I have learnt English for 10 years.

(S+ started+ began+ Ving/ to V+ khoảng thời gian+ ago

= S+ has/ have+ PII/ been Ving+ for+ khoảng thời gian)

5. I have not seen him for ages.

( It has been+ khoảng thời gian+ since+ S+ last+ V2/ Ved

= S+ has/ have+ not+ PII+ for+ khoảng thời gian)